NEW YORK -- After days of denials, a choked-up New York Democratic Rep. Anthony Weiner confessed Monday that he tweeted a bulging-underpants photo of himself to a young woman and admitted to ''inappropriate'' exchanges with six women before and after getting married. He apologized for lying but said he would not resign.

A conservative website that last week started a furor over a lewd photo sent from Weiner's Twitter account posted new photos Monday purportedly from a second woman who said she received shirtless shots of the congressman. At a news conference Monday, Weiner called the initial underpants photo a joke and a ''hugely regrettable mistake.''

BigGovernment.com, the website run by conservative activist Andrew Breitbart, said the new photo was in a cache of intimate online photographs, chats and email exchanges the woman claimed to have. The website did not identify the woman, and it could not immediately be determined if the photo was authentic.

Another photo showed Weiner on a couch with two cats nearby. The website said Weiner sent the photo using the anthonyweiner(at)aol.com account with the subject line ''Me and the pussys.''

The celebrity website RadarOnline.com said a woman claimed to have 200 sexually explicit messages from Weiner through a Facebook account that Weiner no longer uses. It was not clear whether the woman who claimed to have the new photo was the person who claimed to have received the text messages.

In a strange turn before Weiner's planned news conference, Breitbart took to the podium, defending the accuracy of his posts and saying his reputation was being smeared by the congressman.

The photo purportedly showing Weiner shirtless was reminiscent of a photo of former Rep. Chris Lee, a New York Republican who resigned from office earlier this year after a shirtless photo he sent a woman on Craig's List became public.

Weiner had earlier said of the underwear photo that his Twitter account was hacked and that he'd hired a lawyer and a private security firm to get to investigate the incident involving the underwear shot. But he could not say for sure if the underwear photo was of him.

Weiner, 46, married Hillary Rodham Clinton aide Huma Abedin last July, with former President Bill Clinton officiating. Before that, Weiner had been known as one of New York's most eligible bachelors.

Weiner began his career as a legislative assistant to then-Rep. Chuck Schumer, who is now the state's senior senator. He was elected to the New York City Council before winning Schumer's House seat in 1998, representing parts of Brooklyn and Queens.

He gained a national profile during the debate over President Barack Obama's health care plan when he outspokenly professed support for a government-run ''single-payer'' program for everyone and later a ''public option'' to compete with private health insurance. He got the notice of liberals even though both proposals failed to make it into law.